HAMMOND, Ind. — A tow truck operator charged in an alleged bribery scheme has pleaded guilty and agreed to testify for federal prosecutors against an indicted northwestern Indiana sheriff.

Sixty-year-old William Szarmach of C.S.A. Towing in Lake Station on Monday pleaded guilty to charges of bribery, wire fraud and tax evasion.

Szarmach earlier said in a plea agreement filed in federal court that he bought tickets to Lake County Sheriff John Buncich’s fundraising events and made additional cash payments to Buncich between 2009 and 2016 to maintain and increase his business of towing vehicles for county police.

Buncich is scheduled to stand trial beginning Aug. 7 and has said he’s innocent.

The agreement with Szarmach is similar to one made in December with former chief of police Timothy Downs.